<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style>
			.transitionbox{
				width: 250px;
				height: 250px;
				background-image: url(../images/user.jpg);
				/*横向拉伸效果*/
				transition: width 0.1s;
			}
			/*鼠标移入div触发动画执行*/
			.transitionbox:hover{
				background-image: url(../images/user2.jpg);
				width: 750px;/*拉伸到宽度从100到300*/
				height: 550px;
			}
		</style>
	</head>
	<body>
		<h3>拉伸盒子动画效果</h3>
		<h5>transition它有两个参数：拉伸方向width,2s动画执行时间</h5>
		<div class="transitionbox"></div>
	</body>
</html>
